Since 1990, soft plastic drink yokes have been made of low density polyethylene (LDPE) or No. 4 Plastic, which is designed to photo-degrade after 6 months of exposure to UV light. This design feature was in response to the dangers of yokes entering our marine environment and ensnaring wildlife, widespread campaigns have also trained consumers to preempt the risk of harming wildlife; however, even though critters can now trawl through our litter somewhat safely, yokes buried in a landfill will not photo-degrade due to lack of sun exposure.